prf::Rg Class Reference

Radius of gyration of a section of a protein chain. More...

#include <Rg.hh>

Inheritance diagram for prf::Rg:

Public Member Functions
int	init_obs ()
	All observables must implement one initialize routine.
void	of_chain (int i)
	Limit to chain i. If i is -1, all chains.
double	evaluate ()
	Actual calculation of the value of the observable.
void	rangeEstimate (double &x1, double &x2)
	Estimate a range in which values of this observable are expected.
Public Member Functions inherited from prf::Observable
void	set (std::string cmd)
	Give the object an instruction to process during initialization.
virtual void	refresh ()
	Necessary before an observable value is used.
virtual double	delta (Update *u)
	Quick estimate of the change in an Observable due to an update.
double	operator() ()
	Retrieve the value of the observable.
double	Value ()
	Retrieve the value of the observable.
void	disable_stats ()
	Stop collecting statistical data like averages and histograms.
void	enable_stats ()
	Start collecting statistical data like averages and histograms.
Public Member Functions inherited from prf::Named
	Named ()
	Create an object with name "unnamed".
	Named (const char *st)
	Create an object with name st given as a C string.
	Named (std::string st)
	Create an object with a name given as a string.
std::string	Name () const
	Retrive the name of an object.
void	Name (std::string gnm)
	Assign a new name to an object.

Detailed Description

This observable returns the radius of gyration of all non-hydrogen atoms of a given chain or of the whole population. In the case of rg over many chains, it is assumed that EnforceBC has been called, so that all coordinates are within one unit periodic box. Only non-hydrogen atoms are used in the calculation.

Member Function Documentation

int Rg::init_obs ( )

virtual

Even if it seems that one particular observable might need additional arguments during initialization, it is advantageous to have a uniform syntax for all of them. So, when additional arguments are needed, one should provide them in a separate function called before initialization, and then call init_obs without arguments. The name init_obs instead of a more natural "init" or "initialize" is because an Observable often inherits from other classes which represent its character more fundamentally. So, the names such as "init" are kept free for such base classes.

Reimplemented from prf::Observable.

void Rg::rangeEstimate ( double &  x1, double &  x2  )

virtual

The default is between 0 and 1. So, for observables with values always between 0 and 1, you need not over-write this virtual function. Sometimes the observable will have a different fixed range, determined by its definition. Sometimes the range can not be determined perfectly. In such a case, let this function just return something reasonable.

Reimplemented from prf::Observable.

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The documentation for this class was generated from the following files:

• model/Observables/Rg.hh
• model/Observables/Rg.cc